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Film Selector
Guide
Bemis Clysar®
is an extremely versatile family of high-clarity, polyolefin shrink
films designed to satisfy a myriad of packaging needs. From pizza
pies and CD's to the most difficult-to-wrap products, Clysar®
films shrink tight to form a durable, attractive package - time
after time.
Using Clysar® can reduce
your per-unit packaging cost up to 50 percent. That's because the
amount of film you need to wrap a package costs less than the box or
paper you'd need to do the same job. This also means that less waste
goes into landfills.
Clysar® lets you multipack
different shapes, sizes and weights without changing your original
package design. And, for both food and non-food applications, Clysar®
provides the important tamper-evident and tamper-resistant packaging
that today's consumers demand.
All grades of Clysar® are
manufactured in accordance with ISO 9002 standards and comply with
all applicable U.S., European and Canadian regulations for direct
food contact. What's more, Clysar® has received a
"superior" rating from the American Institute of Baking.
All Clysar® films comply
with U.S. Food and Drug Administration (FDA) requirements for food
contact, except for articles used for packing or holding food during
cooking. This FDA compliance and a continuing guarantee from Bemis will meet USDA needs for packaging meat and poultry products. |
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Percent Shrinkage
The oven shrinkage
test measures the area reduction of a 10cm x 10cm unrestrained film
sample held at a given temperature and time (ASTM D1204). Film with
a high percent shrinkage is ideal for wrapping irregular shapes and
minimizing "dog ears."
All Clysar®
films have balanced shrinkage in both MD and TD directions, which
ensures tight packages and increases shelf appeal.
Figure 1.
% Shrinkage - Total
Area
Average value of MD and TD. For comparison, all films were run at
temperatures most suited to polyethylene films. Clysar®
EHC and EZ would typically run at higher temperatures.
(Click to enlarge) |
Shrink Force
Shrink force is the
force exerted by a film, as it is restrained, while attempting to
achieve full shrinkage at a given temperature. Shrink force, which
represents amount of pressure exerted on product being wrapped,
increases with film thickness.
A high shrink force gives
window boxes a taut, wrinkle-free surface and provides stability for
multipacking. A lower shrink force is desirable for wrapping
delicate or think packages that may deform or curl.
Figure 2.
Shrink Force at 230ºF
(110ºC).
Average value of MD and TD.
(Click to enlarge) |
Tear Strength
Elmendorf tear is the
force required to tear, by propagation, a notched film sample. A
high tear strength helps prevent tear propagation when the film is
punctured by uneven or angular product shapes, or needle
perforations.
When using tear strips or
specialty perforations, a low tear strength may be a desirable,
easy-open feature.
Figure 3.
Tear Strength
(Click to enlarge) |
Tensile
Strength
Tensile strength is
the force required to break a 1 inch wide film sample that is pulled
between two grips moving at a fixed speed (ASTM D882).
A high tensile strength gives
improved toughness and durability, high resistance to machine
tension and an easy adjustment for manual feeding operations. A low
tensile strength gives increased puncture resistance and improved
recovery/memory properties.
Figure 4.
Ultimate Tensile
Strength.
Average value of MD and TD.
(Click to enlarge) |
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Modulus
Modulus is a measure of film
stiffness or rigidity. The test is measured using a universal test machine
(ASTM D882). A higher stiffness generally equates to faster running
high-speed films.
A high stiffness ("hard")
film gives low elongation, outstanding performance on high-speed automatic
shrink equipment and excellent printability. A low stiffness
("soft") film gives a softer feel, less "rustle" or
noise and improved conformance to package shape.
Figure 5.
Modulus
Average value of MD and TD.
(Click to enlarge) |
Coefficient of
Friction
Coefficient of friction (COF)
is a measure of how easily film will slip across metal surfaces or other
film surfaces. COF is the ratio of the frictional force to the
gravitational force between the two surfaces in contract (ASTM D1894).
When case packing warm products at
high speeds, there is a tendency for the packages to not slip easily
across each other in the case. Reduced COF of warm items can be
achieved with a surface treatment on Clysar® HPGS,
EZS, LLGS, CHS, VEZS, and VHGS.
Figure 6.
Coefficient of Friction
Film to film.
(Click to enlarge) |
Shrink Tunnel
Temperature
Clysar®
films have a wide range of shrinking temperatures, which makes them
functional on many types of machines. These values can very depending on
tunnel characteristics.
Figure 7.
Shrink Tunnel Temperature.
(Click to enlarge) |
| Table I. Available
Lengths for Clysar® Shrink Films.* |
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-Gauge- |
Core ID,
in. (mm) |
Roll
OD,**
in. (mm) |
50
ft (m) |
60
ft (m) |
75
ft (m) |
100
ft (m) |
125
ft (m) |
150
ft (m) |
3
(76) |
9.5 ± .25
(241) |
10,500
(3,200) |
8,750
(2,667) |
7,000
(2,134) |
5,250
(1,600) |
4,200
(1,280) |
3,500
(1,067) |
3
(76) |
13 ± .25
(330) |
21,000
(6,400) |
17,500
(5,334) |
14,000
(4,268) |
10,500
(3,200) |
8,400
(2,560) |
7,000
(2,134) |
6
(150) |
11 ± .25
(279) |
10,500
(3,200) |
8,750
(2,667) |
7,000
(2,134) |
5,250
(1,600) |
4,200
(1,280) |
3,500
(1,067) |
6
(150) |
14 ± .25
(356) |
|
17,500
(5,334) |
14,000
(4,268) |
10,500
(3,200) |
8,400
(2,560) |
7,000
(2,134) |
6
(150) |
18.75±.25
(476) |
|
35,000
(10,668) |
28,000
(8,534) |
21,000
(6,400) |
16,800
(5,120) |
14,000
(4,268) |
3
(76) |
5
(sample roll) |
1,100
(670) |
925
(564) |
750
(457) |
563
(343) |
450
(274) |
375
(229) |
* Folded films
will have half the linear length of the flat film for the same thickness
and roll dimensions.
Other core diameters and special roll lengths are available upon
request.
** Nominal value; actual OD will vary with gauge and film type. |
Table II. Available
Widths for Clysar® Shrink Films.
(Click to enlarge) |
Table III. Quick
Reference Guide for Clysar® Shrink Films.
(Click to enlarge) |
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